"You will be for me a kingdom of priests and a holy nation." (Exodus 19:6)
Three months after leaving Egypt, Israel arrives at Sinai. God calls to Moses from the mountain: tell the Israelites: you yourselves have seen what I did to Egypt and how I carried you on eagles' wings and brought you to myself. Now if you obey me fully and keep my covenant, then out of all nations you will be my treasured possession, for the whole earth is mine. You will be for me a kingdom of priests and a holy nation. The Catechism identifies this verse as the foundational description of Israel's vocation, fulfilled in the Church as the holy nation called out of every people to be the priestly community that mediates the knowledge of God to all nations (CCC 1546). The election is not for privilege alone but for service: a kingdom of priests, mediating between God and the nations.
Moses comes down and relays the LORD's words. The people answer together: we will do everything the LORD has said. God tells Moses to consecrate the people for two days, washing their clothes, setting limits around the mountain. On the third day the LORD will come down on Mount Sinai in the sight of all the people. The third day arrives: thunder and lightning and a thick cloud and a very loud trumpet blast. The whole mountain is covered in smoke because the LORD has descended on it in fire. The mountain trembles violently. The people tremble too. The Catechism calls this theophany at Sinai the supreme Old Testament revelation of the holy God whose presence produces both awe and desire (CCC 2059).
Brothers and sisters, a kingdom of priests and a holy nation. This is the description of the Church in 1 Peter 2:9, drawn directly from Exodus 19. Every baptised person shares in this priestly calling: not to perform ritual sacrifice but to offer the whole of life to God, to stand between God and the world in intercession, to be the community through which the knowledge of the holy God reaches those who do not yet know him.
Lord God, you brought us on eagles' wings to yourself and made us your treasured possession. Let us be a kingdom of priests and a holy nation, consecrated for the service of your purposes in the world. Through Christ our Lord. Amen.